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???
01/17/13 14:43
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#189221 - final status AT89LP51ED2 reset
Responding to: ???'s previous message
I updated about 20 boards with a pull-up of 560K on pin 'PSEN'.
All but 1 board started up in a good way (10-20 tries), although most of them failed many times without pull-up.
The single board that had 1 failure out of 20, worked well with a pull-up of 330K.

So, for future designs of upgrades, it could be a good idea to place a pull up.

I also remove the LM810 reset chip as this is not needed anymore as the board works on 3V3.

List of 24 messages in thread
TopicAuthorDate
Reset issue with new Atmel AT89LP51ED2            01/01/70 00:00      
   Do never use a µC from which only a preliminary...            01/01/70 00:00      
      configuration settings            01/01/70 00:00      
         what about negative reset?            01/01/70 00:00      
            good idea but            01/01/70 00:00      
   Some things to check...            01/01/70 00:00      
      also try no LM810 at all            01/01/70 00:00      
         reset is inverted            01/01/70 00:00      
      no strange signals            01/01/70 00:00      
         Extra modes ?            01/01/70 00:00      
            pull-up on PSEN solves the problem            01/01/70 00:00      
               small capacitor ?            01/01/70 00:00      
                  small capacitor            01/01/70 00:00      
   side-stepping the problem?            01/01/70 00:00      
      SST could be an option            01/01/70 00:00      
   final status AT89LP51ED2 reset            01/01/70 00:00      
      Clarifies             01/01/70 00:00      
         loads on PSEN            01/01/70 00:00      
            An isolated PSEN works fine ?            01/01/70 00:00      
               GAL causes problem            01/01/70 00:00      
                  ATF16V8CZ has Pin-keeper            01/01/70 00:00      
                     'Z' indeed            01/01/70 00:00      
                        ATF16V8BQL has Icc of ~1.5mA            01/01/70 00:00      
                           'BQL' version could be an option            01/01/70 00:00      

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